At present, work is underway to compile an X‑ray diffractometric determinative guide of metals and alloys. For each crystalline substance, a characteristic X‑ray diffraction pattern is determined. The study of diffraction patterns makes it possible to identify identical substances and distinguish between different ones. The process of determining substances consists of obtaining and calculating the diffraction pattern, and then comparing the results with previously taken reference diffraction patterns of known substances. The set of reference diffraction patterns of metals and alloys will constitute the X‑ray diffractometric determinative guide of metals and alloys.